Vitamin B12 (cyanocobalamine) deficiency is known to cause a wide variety of neurological symptoms. It also seems to produce facial neuralgia, according to a report presented at the International Headache Congress in Philadelphia a week ago. Two physicians from Milwaukee described 17 patients who had facial pain that was not typical of trigeminal neuralgia because they had no trigger area and had numbness on the affected side. They all had vitamin B12 deficiency and they pain improved with injections of vitamin B12. In a previous post I mentioned another study that found an association between migraine headaches and high homocysteine levels, which can also be caused by vitamin B12 deficiency. Oral absorption of vitamin B12 supplements is often inadequate and a nasal spray (which is expensive) or an injection are the best ways to correct this deficiency.

High homocysteine levels increase the risk of cardiovascular disease (strokes and heart attacks) and can be reduced by folic acid and vitamin B12 (cyanocobalamine). A study by Spanish doctors published in Headache found elevated homocysteine levels in patients who have migraines with aura. Patients who have migraine with aura are known to have increased risk of cardiovascular disease and it is possible that elevated homocysteine levels are at least in part responsible for this risk. I routinely check homocysteine, vitamin B12 and folic acid levels in all of my patients. One caveat is that vitamin B12 levels are not very reliable – you may have a normal level, but still be deficient. While laboratories consider a level of over 200 to be normal, clinical deficiency is often present at levels below 400. A single case report has been published of a severe deficiency with neurological symptoms and a vitamin B12 level of over 700. This patient lacked the ability to transport vitamin B12 from his blood into the cells. Injections of high doses of vitamin B12 corrected the problem. Oral magnesium supplementation is not as effective as injections because vitamin B12 is poorly absorbed in the stomach. Other ways to get vitamin B12 is by taking it sublingually (under your tongue) or by a nasal spray (it requires a prescription and is fairly expensive). Many of my patients a willing to self-inject vitamin B12, which they do anywhere fro once a week to once a month. Vegetarians are more likely to be deficient since meat (and liver) are the main sources of vitamin B12. Smokers are also at a high risk because cyanide in smoke binds to vitamin B12.